private void AddTilesIntersectingEnvelopeAt(SpaceFillingCurveConfiguration config, SpaceFillingCurveMonitor monitor, int depth, int maxDepth, SearchEnvelope search, SearchEnvelope currentExtent, CurveRule curve, long left, long right, List <LongRange> results)
{
if (right - left == 1)
{
long[] coord = NormalizedCoordinateFor(left, _maxLevel);
if (search.Contains(coord))
{
LongRange current = (results.Count > 0) ? results[results.Count - 1] : null;
if (current != null && current.Max == left - 1)
{
current.ExpandToMax(left);
}
else
{
current = new LongRange(left);
results.Add(current);
}
if (monitor != null)
{
monitor.AddRangeAtDepth(depth);
monitor.AddToCoveredArea(currentExtent.Area);
}
}
}
else if (search.Intersects(currentExtent))
{
double overlap = search.FractionOf(currentExtent);
if (config.StopAtThisDepth(overlap, depth, maxDepth))
{
// Note that LongRange upper bound is inclusive, hence the '-1' in several places
LongRange current = (results.Count > 0) ? results[results.Count - 1] : null;
if (current != null && current.Max == left - 1)
{
current.ExpandToMax(right - 1);
}
else
{
current = new LongRange(left, right - 1);
results.Add(current);
}
if (monitor != null)
{
monitor.AddRangeAtDepth(depth);
monitor.AddToCoveredArea(currentExtent.Area);
}
}
else
{
long width = (right - left) / _quadFactor;
for (int i = 0; i < _quadFactor; i++)
{
int npoint = curve.NpointForIndex(i);
SearchEnvelope quadrant = currentExtent.Quadrant(BitValues(npoint));
AddTilesIntersectingEnvelopeAt(config, monitor, depth + 1, maxDepth, search, quadrant, curve.ChildAt(i), left + i * width, left + (i + 1) * width, results);
}
}
}
}
internal virtual IList <LongRange> GetTilesIntersectingEnvelope(Envelope referenceEnvelope, SpaceFillingCurveConfiguration config, SpaceFillingCurveMonitor monitor)
{
SearchEnvelope search = new SearchEnvelope(this, referenceEnvelope);
SearchEnvelope wholeExtent = new SearchEnvelope(0, this.Width, _nbrDim);
List <LongRange> results = new List <LongRange>(config.InitialRangesListCapacity());
if (monitor != null)
{
monitor.RegisterSearchArea(search.Area);
}
AddTilesIntersectingEnvelopeAt(config, monitor, 0, config.MaxDepth(referenceEnvelope, this._range, _nbrDim, _maxLevel), search, wholeExtent, RootCurve(), 0, this.ValueWidth, results);
return(results);
}
